1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * kernel/lockdep_proc.c 4 * 5 * Runtime locking correctness validator 6 * 7 * Started by Ingo Molnar: 8 * 9 * Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> 10 * Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra 11 * 12 * Code for /proc/lockdep and /proc/lockdep_stats: 13 * 14 */ 15 #include <linux/export.h> 16 #include <linux/proc_fs.h> 17 #include <linux/seq_file.h> 18 #include <linux/kallsyms.h> 19 #include <linux/debug_locks.h> 20 #include <linux/vmalloc.h> 21 #include <linux/sort.h> 22 #include <linux/uaccess.h> 23 #include <asm/div64.h> 24 25 #include "lockdep_internals.h" 26 27 /* 28 * Since iteration of lock_classes is done without holding the lockdep lock, 29 * it is not safe to iterate all_lock_classes list directly as the iteration 30 * may branch off to free_lock_classes or the zapped list. Iteration is done 31 * directly on the lock_classes array by checking the lock_classes_in_use 32 * bitmap and max_lock_class_idx. 33 */ 34 #define iterate_lock_classes(idx, class) \ 35 for (idx = 0, class = lock_classes; idx <= max_lock_class_idx; \ 36 idx++, class++) 37 l_next(struct seq_file * m,void * v,loff_t * pos)38 static void *l_next(struct seq_file *m, void *v, loff_t *pos) 39 { 40 struct lock_class *class = v; 41 42 ++class; 43 *pos = class - lock_classes; 44 return (*pos > max_lock_class_idx) ? NULL : class; 45 } 46 l_start(struct seq_file * m,loff_t * pos)47 static void *l_start(struct seq_file *m, loff_t *pos) 48 { 49 unsigned long idx = *pos; 50 51 if (idx > max_lock_class_idx) 52 return NULL; 53 return lock_classes + idx; 54 } 55 l_stop(struct seq_file * m,void * v)56 static void l_stop(struct seq_file *m, void *v) 57 { 58 } 59 print_name(struct seq_file * m,struct lock_class * class)60 static void print_name(struct seq_file *m, struct lock_class *class) 61 { 62 char str[KSYM_NAME_LEN]; 63 const char *name = class->name; 64 65 if (!name) { 66 name = __get_key_name(class->key, str); 67 seq_printf(m, "%s", name); 68 } else{ 69 seq_printf(m, "%s", name); 70 if (class->name_version > 1) 71 seq_printf(m, "#%d", class->name_version); 72 if (class->subclass) 73 seq_printf(m, "/%d", class->subclass); 74 } 75 } 76 l_show(struct seq_file * m,void * v)77 static int l_show(struct seq_file *m, void *v) 78 { 79 struct lock_class *class = v; 80 struct lock_list *entry; 81 char usage[LOCK_USAGE_CHARS]; 82 int idx = class - lock_classes; 83 84 if (v == lock_classes) 85 seq_printf(m, "all lock classes:\n"); 86 87 if (!test_bit(idx, lock_classes_in_use)) 88 return 0; 89 90 seq_printf(m, "%p", class->key); 91 #ifdef CONFIG_DEBUG_LOCKDEP 92 seq_printf(m, " OPS:%8ld", debug_class_ops_read(class)); 93 #endif 94 if (IS_ENABLED(CONFIG_PROVE_LOCKING)) { 95 seq_printf(m, " FD:%5ld", lockdep_count_forward_deps(class)); 96 seq_printf(m, " BD:%5ld", lockdep_count_backward_deps(class)); 97 98 get_usage_chars(class, usage); 99 seq_printf(m, " %s", usage); 100 } 101 102 seq_printf(m, ": "); 103 print_name(m, class); 104 seq_puts(m, "\n"); 105 106 if (IS_ENABLED(CONFIG_PROVE_LOCKING)) { 107 list_for_each_entry(entry, &class->locks_after, entry) { 108 if (entry->distance == 1) { 109 seq_printf(m, " -> [%p] ", entry->class->key); 110 print_name(m, entry->class); 111 seq_puts(m, "\n"); 112 } 113 } 114 seq_puts(m, "\n"); 115 } 116 117 return 0; 118 } 119 120 static const struct seq_operations lockdep_ops = { 121 .start = l_start, 122 .next = l_next, 123 .stop = l_stop, 124 .show = l_show, 125 }; 126 127 #ifdef CONFIG_PROVE_LOCKING lc_start(struct seq_file * m,loff_t * pos)128 static void *lc_start(struct seq_file *m, loff_t *pos) 129 { 130 if (*pos < 0) 131 return NULL; 132 133 if (*pos == 0) 134 return SEQ_START_TOKEN; 135 136 return lock_chains + (*pos - 1); 137 } 138 lc_next(struct seq_file * m,void * v,loff_t * pos)139 static void *lc_next(struct seq_file *m, void *v, loff_t *pos) 140 { 141 *pos = lockdep_next_lockchain(*pos - 1) + 1; 142 return lc_start(m, pos); 143 } 144 lc_stop(struct seq_file * m,void * v)145 static void lc_stop(struct seq_file *m, void *v) 146 { 147 } 148 lc_show(struct seq_file * m,void * v)149 static int lc_show(struct seq_file *m, void *v) 150 { 151 struct lock_chain *chain = v; 152 struct lock_class *class; 153 int i; 154 static const char * const irq_strs[] = { 155 [0] = "0", 156 [LOCK_CHAIN_HARDIRQ_CONTEXT] = "hardirq", 157 [LOCK_CHAIN_SOFTIRQ_CONTEXT] = "softirq", 158 [LOCK_CHAIN_SOFTIRQ_CONTEXT| 159 LOCK_CHAIN_HARDIRQ_CONTEXT] = "hardirq|softirq", 160 }; 161 162 if (v == SEQ_START_TOKEN) { 163 if (!nr_free_chain_hlocks) 164 seq_printf(m, "(buggered) "); 165 seq_printf(m, "all lock chains:\n"); 166 return 0; 167 } 168 169 seq_printf(m, "irq_context: %s\n", irq_strs[chain->irq_context]); 170 171 for (i = 0; i < chain->depth; i++) { 172 class = lock_chain_get_class(chain, i); 173 if (!class->key) 174 continue; 175 176 seq_printf(m, "[%p] ", class->key); 177 print_name(m, class); 178 seq_puts(m, "\n"); 179 } 180 seq_puts(m, "\n"); 181 182 return 0; 183 } 184 185 static const struct seq_operations lockdep_chains_ops = { 186 .start = lc_start, 187 .next = lc_next, 188 .stop = lc_stop, 189 .show = lc_show, 190 }; 191 #endif /* CONFIG_PROVE_LOCKING */ 192 lockdep_stats_debug_show(struct seq_file * m)193 static void lockdep_stats_debug_show(struct seq_file *m) 194 { 195 #ifdef CONFIG_DEBUG_LOCKDEP 196 unsigned long long hi1 = debug_atomic_read(hardirqs_on_events), 197 hi2 = debug_atomic_read(hardirqs_off_events), 198 hr1 = debug_atomic_read(redundant_hardirqs_on), 199 hr2 = debug_atomic_read(redundant_hardirqs_off), 200 si1 = debug_atomic_read(softirqs_on_events), 201 si2 = debug_atomic_read(softirqs_off_events), 202 sr1 = debug_atomic_read(redundant_softirqs_on), 203 sr2 = debug_atomic_read(redundant_softirqs_off); 204 205 seq_printf(m, " chain lookup misses: %11llu\n", 206 debug_atomic_read(chain_lookup_misses)); 207 seq_printf(m, " chain lookup hits: %11llu\n", 208 debug_atomic_read(chain_lookup_hits)); 209 seq_printf(m, " cyclic checks: %11llu\n", 210 debug_atomic_read(nr_cyclic_checks)); 211 seq_printf(m, " redundant checks: %11llu\n", 212 debug_atomic_read(nr_redundant_checks)); 213 seq_printf(m, " redundant links: %11llu\n", 214 debug_atomic_read(nr_redundant)); 215 seq_printf(m, " find-mask forwards checks: %11llu\n", 216 debug_atomic_read(nr_find_usage_forwards_checks)); 217 seq_printf(m, " find-mask backwards checks: %11llu\n", 218 debug_atomic_read(nr_find_usage_backwards_checks)); 219 220 seq_printf(m, " hardirq on events: %11llu\n", hi1); 221 seq_printf(m, " hardirq off events: %11llu\n", hi2); 222 seq_printf(m, " redundant hardirq ons: %11llu\n", hr1); 223 seq_printf(m, " redundant hardirq offs: %11llu\n", hr2); 224 seq_printf(m, " softirq on events: %11llu\n", si1); 225 seq_printf(m, " softirq off events: %11llu\n", si2); 226 seq_printf(m, " redundant softirq ons: %11llu\n", sr1); 227 seq_printf(m, " redundant softirq offs: %11llu\n", sr2); 228 #endif 229 } 230 lockdep_stats_show(struct seq_file * m,void * v)231 static int lockdep_stats_show(struct seq_file *m, void *v) 232 { 233 unsigned long nr_unused = 0, nr_uncategorized = 0, 234 nr_irq_safe = 0, nr_irq_unsafe = 0, 235 nr_softirq_safe = 0, nr_softirq_unsafe = 0, 236 nr_hardirq_safe = 0, nr_hardirq_unsafe = 0, 237 nr_irq_read_safe = 0, nr_irq_read_unsafe = 0, 238 nr_softirq_read_safe = 0, nr_softirq_read_unsafe = 0, 239 nr_hardirq_read_safe = 0, nr_hardirq_read_unsafe = 0, 240 sum_forward_deps = 0; 241 242 #ifdef CONFIG_PROVE_LOCKING 243 struct lock_class *class; 244 unsigned long idx; 245 246 iterate_lock_classes(idx, class) { 247 if (!test_bit(idx, lock_classes_in_use)) 248 continue; 249 250 if (class->usage_mask == 0) 251 nr_unused++; 252 if (class->usage_mask == LOCKF_USED) 253 nr_uncategorized++; 254 if (class->usage_mask & LOCKF_USED_IN_IRQ) 255 nr_irq_safe++; 256 if (class->usage_mask & LOCKF_ENABLED_IRQ) 257 nr_irq_unsafe++; 258 if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ) 259 nr_softirq_safe++; 260 if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ) 261 nr_softirq_unsafe++; 262 if (class->usage_mask & LOCKF_USED_IN_HARDIRQ) 263 nr_hardirq_safe++; 264 if (class->usage_mask & LOCKF_ENABLED_HARDIRQ) 265 nr_hardirq_unsafe++; 266 if (class->usage_mask & LOCKF_USED_IN_IRQ_READ) 267 nr_irq_read_safe++; 268 if (class->usage_mask & LOCKF_ENABLED_IRQ_READ) 269 nr_irq_read_unsafe++; 270 if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ) 271 nr_softirq_read_safe++; 272 if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ_READ) 273 nr_softirq_read_unsafe++; 274 if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ) 275 nr_hardirq_read_safe++; 276 if (class->usage_mask & LOCKF_ENABLED_HARDIRQ_READ) 277 nr_hardirq_read_unsafe++; 278 279 sum_forward_deps += lockdep_count_forward_deps(class); 280 } 281 282 #ifdef CONFIG_DEBUG_LOCKDEP 283 DEBUG_LOCKS_WARN_ON(debug_atomic_read(nr_unused_locks) != nr_unused); 284 #endif 285 286 #endif 287 seq_printf(m, " lock-classes: %11lu [max: %lu]\n", 288 nr_lock_classes, MAX_LOCKDEP_KEYS); 289 seq_printf(m, " direct dependencies: %11lu [max: %lu]\n", 290 nr_list_entries, MAX_LOCKDEP_ENTRIES); 291 seq_printf(m, " indirect dependencies: %11lu\n", 292 sum_forward_deps); 293 294 /* 295 * Total number of dependencies: 296 * 297 * All irq-safe locks may nest inside irq-unsafe locks, 298 * plus all the other known dependencies: 299 */ 300 seq_printf(m, " all direct dependencies: %11lu\n", 301 nr_irq_unsafe * nr_irq_safe + 302 nr_hardirq_unsafe * nr_hardirq_safe + 303 nr_list_entries); 304 305 #ifdef CONFIG_PROVE_LOCKING 306 seq_printf(m, " dependency chains: %11lu [max: %lu]\n", 307 lock_chain_count(), MAX_LOCKDEP_CHAINS); 308 seq_printf(m, " dependency chain hlocks used: %11lu [max: %lu]\n", 309 MAX_LOCKDEP_CHAIN_HLOCKS - 310 (nr_free_chain_hlocks + nr_lost_chain_hlocks), 311 MAX_LOCKDEP_CHAIN_HLOCKS); 312 seq_printf(m, " dependency chain hlocks lost: %11u\n", 313 nr_lost_chain_hlocks); 314 #endif 315 316 #ifdef CONFIG_TRACE_IRQFLAGS 317 seq_printf(m, " in-hardirq chains: %11u\n", 318 nr_hardirq_chains); 319 seq_printf(m, " in-softirq chains: %11u\n", 320 nr_softirq_chains); 321 #endif 322 seq_printf(m, " in-process chains: %11u\n", 323 nr_process_chains); 324 seq_printf(m, " stack-trace entries: %11lu [max: %lu]\n", 325 nr_stack_trace_entries, MAX_STACK_TRACE_ENTRIES); 326 #if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING) 327 seq_printf(m, " number of stack traces: %11llu\n", 328 lockdep_stack_trace_count()); 329 seq_printf(m, " number of stack hash chains: %11llu\n", 330 lockdep_stack_hash_count()); 331 #endif 332 seq_printf(m, " combined max dependencies: %11u\n", 333 (nr_hardirq_chains + 1) * 334 (nr_softirq_chains + 1) * 335 (nr_process_chains + 1) 336 ); 337 seq_printf(m, " hardirq-safe locks: %11lu\n", 338 nr_hardirq_safe); 339 seq_printf(m, " hardirq-unsafe locks: %11lu\n", 340 nr_hardirq_unsafe); 341 seq_printf(m, " softirq-safe locks: %11lu\n", 342 nr_softirq_safe); 343 seq_printf(m, " softirq-unsafe locks: %11lu\n", 344 nr_softirq_unsafe); 345 seq_printf(m, " irq-safe locks: %11lu\n", 346 nr_irq_safe); 347 seq_printf(m, " irq-unsafe locks: %11lu\n", 348 nr_irq_unsafe); 349 350 seq_printf(m, " hardirq-read-safe locks: %11lu\n", 351 nr_hardirq_read_safe); 352 seq_printf(m, " hardirq-read-unsafe locks: %11lu\n", 353 nr_hardirq_read_unsafe); 354 seq_printf(m, " softirq-read-safe locks: %11lu\n", 355 nr_softirq_read_safe); 356 seq_printf(m, " softirq-read-unsafe locks: %11lu\n", 357 nr_softirq_read_unsafe); 358 seq_printf(m, " irq-read-safe locks: %11lu\n", 359 nr_irq_read_safe); 360 seq_printf(m, " irq-read-unsafe locks: %11lu\n", 361 nr_irq_read_unsafe); 362 363 seq_printf(m, " uncategorized locks: %11lu\n", 364 nr_uncategorized); 365 seq_printf(m, " unused locks: %11lu\n", 366 nr_unused); 367 seq_printf(m, " max locking depth: %11u\n", 368 max_lockdep_depth); 369 #ifdef CONFIG_PROVE_LOCKING 370 seq_printf(m, " max bfs queue depth: %11u\n", 371 max_bfs_queue_depth); 372 #endif 373 seq_printf(m, " max lock class index: %11lu\n", 374 max_lock_class_idx); 375 lockdep_stats_debug_show(m); 376 seq_printf(m, " debug_locks: %11u\n", 377 debug_locks); 378 379 /* 380 * Zapped classes and lockdep data buffers reuse statistics. 381 */ 382 seq_puts(m, "\n"); 383 seq_printf(m, " zapped classes: %11lu\n", 384 nr_zapped_classes); 385 #ifdef CONFIG_PROVE_LOCKING 386 seq_printf(m, " zapped lock chains: %11lu\n", 387 nr_zapped_lock_chains); 388 seq_printf(m, " large chain blocks: %11u\n", 389 nr_large_chain_blocks); 390 #endif 391 return 0; 392 } 393 394 #ifdef CONFIG_LOCK_STAT 395 396 struct lock_stat_data { 397 struct lock_class *class; 398 struct lock_class_stats stats; 399 }; 400 401 struct lock_stat_seq { 402 struct lock_stat_data *iter_end; 403 struct lock_stat_data stats[MAX_LOCKDEP_KEYS]; 404 }; 405 406 /* 407 * sort on absolute number of contentions 408 */ lock_stat_cmp(const void * l,const void * r)409 static int lock_stat_cmp(const void *l, const void *r) 410 { 411 const struct lock_stat_data *dl = l, *dr = r; 412 unsigned long nl, nr; 413 414 nl = dl->stats.read_waittime.nr + dl->stats.write_waittime.nr; 415 nr = dr->stats.read_waittime.nr + dr->stats.write_waittime.nr; 416 417 return nr - nl; 418 } 419 seq_line(struct seq_file * m,char c,int offset,int length)420 static void seq_line(struct seq_file *m, char c, int offset, int length) 421 { 422 int i; 423 424 for (i = 0; i < offset; i++) 425 seq_puts(m, " "); 426 for (i = 0; i < length; i++) 427 seq_printf(m, "%c", c); 428 seq_puts(m, "\n"); 429 } 430 snprint_time(char * buf,size_t bufsiz,s64 nr)431 static void snprint_time(char *buf, size_t bufsiz, s64 nr) 432 { 433 s64 div; 434 s32 rem; 435 436 nr += 5; /* for display rounding */ 437 div = div_s64_rem(nr, 1000, &rem); 438 snprintf(buf, bufsiz, "%lld.%02d", (long long)div, (int)rem/10); 439 } 440 seq_time(struct seq_file * m,s64 time)441 static void seq_time(struct seq_file *m, s64 time) 442 { 443 char num[15]; 444 445 snprint_time(num, sizeof(num), time); 446 seq_printf(m, " %14s", num); 447 } 448 seq_lock_time(struct seq_file * m,struct lock_time * lt)449 static void seq_lock_time(struct seq_file *m, struct lock_time *lt) 450 { 451 seq_printf(m, "%14lu", lt->nr); 452 seq_time(m, lt->min); 453 seq_time(m, lt->max); 454 seq_time(m, lt->total); 455 seq_time(m, lt->nr ? div64_u64(lt->total, lt->nr) : 0); 456 } 457 seq_stats(struct seq_file * m,struct lock_stat_data * data)458 static void seq_stats(struct seq_file *m, struct lock_stat_data *data) 459 { 460 const struct lockdep_subclass_key *ckey; 461 struct lock_class_stats *stats; 462 struct lock_class *class; 463 const char *cname; 464 int i, namelen; 465 char name[39]; 466 467 class = data->class; 468 stats = &data->stats; 469 470 namelen = 38; 471 if (class->name_version > 1) 472 namelen -= 2; /* XXX truncates versions > 9 */ 473 if (class->subclass) 474 namelen -= 2; 475 476 rcu_read_lock_sched(); 477 cname = rcu_dereference_sched(class->name); 478 ckey = rcu_dereference_sched(class->key); 479 480 if (!cname && !ckey) { 481 rcu_read_unlock_sched(); 482 return; 483 484 } else if (!cname) { 485 char str[KSYM_NAME_LEN]; 486 const char *key_name; 487 488 key_name = __get_key_name(ckey, str); 489 snprintf(name, namelen, "%s", key_name); 490 } else { 491 snprintf(name, namelen, "%s", cname); 492 } 493 rcu_read_unlock_sched(); 494 495 namelen = strlen(name); 496 if (class->name_version > 1) { 497 snprintf(name+namelen, 3, "#%d", class->name_version); 498 namelen += 2; 499 } 500 if (class->subclass) { 501 snprintf(name+namelen, 3, "/%d", class->subclass); 502 namelen += 2; 503 } 504 505 if (stats->write_holdtime.nr) { 506 if (stats->read_holdtime.nr) 507 seq_printf(m, "%38s-W:", name); 508 else 509 seq_printf(m, "%40s:", name); 510 511 seq_printf(m, "%14lu ", stats->bounces[bounce_contended_write]); 512 seq_lock_time(m, &stats->write_waittime); 513 seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_write]); 514 seq_lock_time(m, &stats->write_holdtime); 515 seq_puts(m, "\n"); 516 } 517 518 if (stats->read_holdtime.nr) { 519 seq_printf(m, "%38s-R:", name); 520 seq_printf(m, "%14lu ", stats->bounces[bounce_contended_read]); 521 seq_lock_time(m, &stats->read_waittime); 522 seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_read]); 523 seq_lock_time(m, &stats->read_holdtime); 524 seq_puts(m, "\n"); 525 } 526 527 if (stats->read_waittime.nr + stats->write_waittime.nr == 0) 528 return; 529 530 if (stats->read_holdtime.nr) 531 namelen += 2; 532 533 for (i = 0; i < LOCKSTAT_POINTS; i++) { 534 char ip[32]; 535 536 if (class->contention_point[i] == 0) 537 break; 538 539 if (!i) 540 seq_line(m, '-', 40-namelen, namelen); 541 542 snprintf(ip, sizeof(ip), "[<%p>]", 543 (void *)class->contention_point[i]); 544 seq_printf(m, "%40s %14lu %29s %pS\n", 545 name, stats->contention_point[i], 546 ip, (void *)class->contention_point[i]); 547 } 548 for (i = 0; i < LOCKSTAT_POINTS; i++) { 549 char ip[32]; 550 551 if (class->contending_point[i] == 0) 552 break; 553 554 if (!i) 555 seq_line(m, '-', 40-namelen, namelen); 556 557 snprintf(ip, sizeof(ip), "[<%p>]", 558 (void *)class->contending_point[i]); 559 seq_printf(m, "%40s %14lu %29s %pS\n", 560 name, stats->contending_point[i], 561 ip, (void *)class->contending_point[i]); 562 } 563 if (i) { 564 seq_puts(m, "\n"); 565 seq_line(m, '.', 0, 40 + 1 + 12 * (14 + 1)); 566 seq_puts(m, "\n"); 567 } 568 } 569 seq_header(struct seq_file * m)570 static void seq_header(struct seq_file *m) 571 { 572 seq_puts(m, "lock_stat version 0.4\n"); 573 574 if (unlikely(!debug_locks)) 575 seq_printf(m, "*WARNING* lock debugging disabled!! - possibly due to a lockdep warning\n"); 576 577 seq_line(m, '-', 0, 40 + 1 + 12 * (14 + 1)); 578 seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s %14s %14s " 579 "%14s %14s\n", 580 "class name", 581 "con-bounces", 582 "contentions", 583 "waittime-min", 584 "waittime-max", 585 "waittime-total", 586 "waittime-avg", 587 "acq-bounces", 588 "acquisitions", 589 "holdtime-min", 590 "holdtime-max", 591 "holdtime-total", 592 "holdtime-avg"); 593 seq_line(m, '-', 0, 40 + 1 + 12 * (14 + 1)); 594 seq_printf(m, "\n"); 595 } 596 ls_start(struct seq_file * m,loff_t * pos)597 static void *ls_start(struct seq_file *m, loff_t *pos) 598 { 599 struct lock_stat_seq *data = m->private; 600 struct lock_stat_data *iter; 601 602 if (*pos == 0) 603 return SEQ_START_TOKEN; 604 605 iter = data->stats + (*pos - 1); 606 if (iter >= data->iter_end) 607 iter = NULL; 608 609 return iter; 610 } 611 ls_next(struct seq_file * m,void * v,loff_t * pos)612 static void *ls_next(struct seq_file *m, void *v, loff_t *pos) 613 { 614 (*pos)++; 615 return ls_start(m, pos); 616 } 617 ls_stop(struct seq_file * m,void * v)618 static void ls_stop(struct seq_file *m, void *v) 619 { 620 } 621 ls_show(struct seq_file * m,void * v)622 static int ls_show(struct seq_file *m, void *v) 623 { 624 if (v == SEQ_START_TOKEN) 625 seq_header(m); 626 else 627 seq_stats(m, v); 628 629 return 0; 630 } 631 632 static const struct seq_operations lockstat_ops = { 633 .start = ls_start, 634 .next = ls_next, 635 .stop = ls_stop, 636 .show = ls_show, 637 }; 638 lock_stat_open(struct inode * inode,struct file * file)639 static int lock_stat_open(struct inode *inode, struct file *file) 640 { 641 int res; 642 struct lock_class *class; 643 struct lock_stat_seq *data = vmalloc(sizeof(struct lock_stat_seq)); 644 645 if (!data) 646 return -ENOMEM; 647 648 res = seq_open(file, &lockstat_ops); 649 if (!res) { 650 struct lock_stat_data *iter = data->stats; 651 struct seq_file *m = file->private_data; 652 unsigned long idx; 653 654 iterate_lock_classes(idx, class) { 655 if (!test_bit(idx, lock_classes_in_use)) 656 continue; 657 iter->class = class; 658 iter->stats = lock_stats(class); 659 iter++; 660 } 661 662 data->iter_end = iter; 663 664 sort(data->stats, data->iter_end - data->stats, 665 sizeof(struct lock_stat_data), 666 lock_stat_cmp, NULL); 667 668 m->private = data; 669 } else 670 vfree(data); 671 672 return res; 673 } 674 lock_stat_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)675 static ssize_t lock_stat_write(struct file *file, const char __user *buf, 676 size_t count, loff_t *ppos) 677 { 678 struct lock_class *class; 679 unsigned long idx; 680 char c; 681 682 if (count) { 683 if (get_user(c, buf)) 684 return -EFAULT; 685 686 if (c != '0') 687 return count; 688 689 iterate_lock_classes(idx, class) { 690 if (!test_bit(idx, lock_classes_in_use)) 691 continue; 692 clear_lock_stats(class); 693 } 694 } 695 return count; 696 } 697 lock_stat_release(struct inode * inode,struct file * file)698 static int lock_stat_release(struct inode *inode, struct file *file) 699 { 700 struct seq_file *seq = file->private_data; 701 702 vfree(seq->private); 703 return seq_release(inode, file); 704 } 705 706 static const struct proc_ops lock_stat_proc_ops = { 707 .proc_open = lock_stat_open, 708 .proc_write = lock_stat_write, 709 .proc_read = seq_read, 710 .proc_lseek = seq_lseek, 711 .proc_release = lock_stat_release, 712 }; 713 #endif /* CONFIG_LOCK_STAT */ 714 lockdep_proc_init(void)715 static int __init lockdep_proc_init(void) 716 { 717 proc_create_seq("lockdep", S_IRUSR, NULL, &lockdep_ops); 718 #ifdef CONFIG_PROVE_LOCKING 719 proc_create_seq("lockdep_chains", S_IRUSR, NULL, &lockdep_chains_ops); 720 #endif 721 proc_create_single("lockdep_stats", S_IRUSR, NULL, lockdep_stats_show); 722 #ifdef CONFIG_LOCK_STAT 723 proc_create("lock_stat", S_IRUSR | S_IWUSR, NULL, &lock_stat_proc_ops); 724 #endif 725 726 return 0; 727 } 728 729 __initcall(lockdep_proc_init); 730 731